The impact of others' emotional interactions on young children was assessed in a programmatic series of home and laboratory studies. Others' angry interactions in the environment of the child, but not directed to the child, frequently produced overt distress in both preschoolers and school-age children. Patterns of children's emotional responding to others' anger tended to be stable across time. Frequent exposure to interparent hostility resulted in increased visible disturbance in the child. Both preschool and school-age children most often responded to others' affection with smiling, laughing and/or attempts to participate in affectionate interactions. A series of laboratory studies involving two-year old children demonstrated that exposure to anger between adults tended to increase the intensity of later aggression towards peers. Observations of affiliative or prosocial interactions between adults reduced the frequency and intensity of the child's aggression toward peers. In contrast, others' angry and prosocial interactions had little effect on altruism towards peers. This research indicates the need to consider the ambient emotional climate in the home as a factor in early emotional development.